There is a global increase in the number of migrant workers, both skilled and unskilled. Singapore is one of Asia’s most prosperous countries, with similar per capita Gross Domestic Product (GDP) to that of leading nations in Western Europe [1]. In 2012, unemployment rates among Singaporean citizens and permanent residents were at a low of 2.8% [2]. In view of its small population of 5 million, declining birth rates (7.7 per 1000 population in 2012), ageing populace and rising cost of living, Singapore imports migrant workers to reduce labour shortages [3, 4]. Transient labour forces from neighbouring countries are lured by the higher wages they can earn in Singapore [5, 6].

According to the Asian code of piety, women should care for children and older adults, in addition to being responsible for housekeeping [7, 8]. However, over the last four decades, Singapore has experienced an increase in the number of women entering the workforce, as dual income has become necessary to meet the rising cost of living [9]. This reflects a global pattern producing a ‘global care chain’ [10, 11] in which a cyclical demand for domestic workers is created as women enter the work force, and women migrate to fill their domestic roles. This cycle both contributes to development in receiving countries, and deficits in domestic roles (e.g. carers of ‘left behind families’) in sending countries [12].

With an increasing demand for domestic workers, in 1978 the Singaporean government introduced the Foreign Domestic Worker Scheme to meet this need. By 2015, there were over 230,000 migrant domestic workers (MDWs) in Singapore compared with 20,000 in 1987 [13, 14]. While the state has acknowledged the need for domestic help, there are numerous restrictions on MDWs as a condition of their work permits. For example, MDWs are prohibited from settling permanently in Singapore [4]. Regulatory measures introduced by the state include inter-alia a two-year working contract, minimum age of 18 (raised to 23 on 1 January 2005), and the prohibition of pregnancy with or marriage to Singaporeans [15]. Hitherto, family members are prohibited from joining MDWs in Singapore. This has detrimental effects not only on the overall health and quality of life of MDWs, but also on their families left-behind [16], and there is a body of literature documenting the mental and physical effects of occupational stressors, as well as exposure to exploitation and abuse, among labour migrants [17–20].

MDWs also often face arbitrary rules not enforceable under law. They are bound by the contracts set by their individual employers who also sponsor their work permits. Although workers have the option to reject the terms of employment, there is pressure to accept these terms in order to retain their employment contracts and work permits, and be able to remit money home. MDWs are also excluded from the Employment Act, the key legislation that covers employment conditions for workers in Singapore [15]. For example, MDWs often work around the clock, as there are no stipulated working hours. Bullying or abuse also often occurs, as workers are required to live with their employers [4]. They are deterred from filing a complaint when abused as their work permits may be cancelled. This makes them vulnerable to high levels of stress, mental and physical strain, social isolation and a lower quality of life.

In 2014, a Burmese female MDW broke both legs while escaping from her employer’s high-rise condominium, causing a strain on Burma-Singapore relations and leading to a ban of Burmese workers going to Singapore [21–23]. Exploitation and abuse among MDWs, and the strain in bilateral relationships resulting from cases of this, are not limited to Singapore and its labour suppliers. For example, there are reports that MDWs in the Arab states face sexual abuse, harassment, and 21-h days. The Kefala system in the Arab states ties MDWs to their employers in a visa sponsorship system much like in Singapore. This means that MDWs are unable to switch jobs without their employer’s permission [24, 25].

While the Singapore government has mandated a weekly day off with effect from 1 January 2013 [15], workers may negotiate exchanging their days off for extra money. As some employers still believe that workers’ entitlement to weekly rest days (and their resulting freedom) may be problematic, and because of the profitability of increased work hours for employees [26], many employers arrange to compensate them in exchange for no days off.

Stress and mental health are inversely related [27]. The World Health Organization defines mental health as “a state of well-being in which the individual…can cope with the stresses of life” [28]. According to the Demand-Control Theory of stress, people working in high-strain jobs are more prone to a range of psychological and physical problems [29]. MDW’s roles are characterised by excessive demands and limited autonomy, which predispose a worker to psychological ill health. Although no previous research has investigated quality of life among MDWs, suicide figures shed some light on this [30]. Between 1999 and 2005, 147 MDWs were reported to have died from accident or suicide [31], and suicide is underreported and often recorded as another cause of death. Human Rights Watch reported that poor working conditions, anxiety over unpaid debts, social isolation and prolonged confinements were cited by workers’ peers as reasons for suicide [31].

The Demand-Control Theory of stress also acknowledges how social support can impact on psychosocial health [29]. Good social support has been found to protect against the detrimental effects of work demands, and higher levels of autonomy and social support have been linked to better quality of life [32]. Forced to live with their employers, MDWs may lack social support and positive relationships outside work, especially if they have no access to a weekly day off. An advocate of migrant workers’ rights stated: “Many 'no day off' employers do their utmost to cut off their workers from communication with the outside world. I am certain that it is damaging to their mental health, so that suicides and the infliction of harm on employers' family members should be seen in this context”. This suggests that stressful working conditions and a lack of social support may contribute to harmful behaviours to self or others.

Though MDWs may be at increased risk of poor mental health and quality of life, there is a lack of empirical research on this population. Most academic publications focus on migration economics and the social implications of MDWs’ presence in Singapore. However, it is becoming necessary to look at their general quality of life following the legalisation of a weekly day off for MDWs and the subsequent lobbying to place them under the Employment Act. This is especially salient as there are employers who doubt the benefits of a weekly day off [8]. While cases of MDW abuse reported in the media only comprise a small fraction of the population, this can be likened to the tip of an iceberg. The majority of workers do not receive attention in a typical ‘out of sight, out of mind’ paradigm. Understanding their socio-demographic characteristics, stress, social connectivity, health, and quality of life may assist policy makers in developing pro-health policies that are neither a reaction to bad press nor subject to voters’ demands. This is especially important as Singapore, Indonesia, and the Philippines, among others, entered into the ASEAN Economic Community on 1 January 2016, facilitating labour movement between member countries.

In addition, there is a global increase in attention towards migrant worker issues, in the context of migration, mental health in the workplace, social justice and human rights, as well as the global suicide agenda. Human Rights Watch in 2014 published a qualitative case study with 99 MDWs in the United Arab Emirates, eerily titled “I already bought you” expressing the sentiments of many Arab employers of MDWs [33]. Unfortunately, in Singapore, the sentiment is perhaps similar. Information gathered in this study contributes to the wider literature on migrant worker issues, providing the so-called population norm for the quality of life and social connectivity of MDWs in general, against which individual comparisons may be made.

The findings suggested that participants had a good level of satisfaction with overall quality of life and health. Interestingly, age and work experience were found to be positively associated with health and quality of life, with older women with more working experience reporting better quality of life across most domains. 63.3% of women reported agreement between experienced and preferred working management style, which was also associated with higher health and quality of life scores. More than half of participants reported feeling stressed, which was significantly associated with poorer quality of life.

Nearly 20% of participants reported being ‘Isolated’ or ‘Very Isolated’ despite having access to rest days, which is higher than the normative percentage for the Friendship Scale instrument [36]. Social support was found to be inversely related to stress, health, and quality of life, and MDWs who reported feeling stressed were more likely to be isolated. On the other hand, very socially connected women showed the highest quality of life scores. This may partly explain why older workers and those with more work experience had improved quality of life scores, as they are likely to have better social support.

The association between social connectivity and quality of life is in line with the Demand-Control Theory. This is also consistent with previous research demonstrating the relationship between social isolation and poor health outcomes, and the protective effects of social support [38–41], and reflects research suggesting that the six dimensions of the Friendship Scale (ease in relating with others; isolation from others; having someone to share with; ease to get in touch; feeling separate from others; and loneliness) are associated with self-esteem and the psychological and social domains of the WHOQoL-Bréf [36]. The salience of social isolation may be particularly significant for these migrant women due to the loss of social support through migration, which has also been shown to have a negative effect on psychological health and quality of life [42–49], and is consistent with previous research highlighting the significance of social isolation among migrants, and its relationship with poorer health outcomes [50–54].

A mismatch between pre-migration aspirations and the reality of work may increase stress and contribute to poorer quality of life among new MDWs [55]. On the contrary, older and more experienced workers could have developed more effective stress coping strategies. More experienced workers may also be more acculturated and have adjusted to the host country, resulting in fewer experiences of stressful situations. Accordingly, they might have formed better social support networks, and acquired access to social and health resources. Older and more experienced FMDWs may also have learned to manage expectations better, resulting in better quality of life. There is very limited data on the relationship between migration, age, time since migration, social support, and health among migrant domestic workers – particularly those who migrate without their families or other social support networks. Furthermore, the evidence is inconsistent, with research suggesting both that greater time since migration is not associated with increased social integration or access to social support resources [56], and that greater length of residency is associated with improved health outcomes [57].

It should be noted that the stress these communities experience is likely to be multidimensional, and lower quality of life may be caused not only by a single stressor but also the continuing effects of other life events or chronic stress [58]. MDWs may be exposed to a range of stressors including financial burden, separation from family, violence, exploitation, immigration challenges, culture shock, language barriers, limited agency and being overworked, which may contribute to poor quality of life, social isolation, and stress. This is highlighted in a recent survey of MDWs in Singapore, which identified that 24% of women had poor mental health, 74% experienced restriction of movement, 51% had been verbally abused, and 40% were given less than one rest day a week [59].

There may be additional factors which are contributing to these outcomes among MDWs. For example, the theory of selective migration argues that people with poorer social skills or fewer social networks may migrate for work rather than stay in their hometowns [60]. As a result, these workers may report lower ratings on the Social Relationship domain of quality of life. Further research should be conducted to examine these aspects.

Low-skilled migrant workers face difficulties in accessing health services in many countries, let alone mental health or social services, due to lack of entitlement/access, language barriers, strict working hours, and lack of knowledge of services available in host countries [4, 9, 31, 61]. Workers’ poorer quality of life can result in decreased productivity [32, 62–69], and may also result in other social consequences, for example antisocial or criminal behaviour [70–73], or poor health outcomes [64–69]. The current study highlights the social and health needs of this population, and is consistent with previous research elsewhere including Hong Kong and Spain, pointing to the stressors and risk of exploitation experienced by domestic workers [74, 75]. Our findings point to the urgent need for immigration and employment policies promoting workers’ well-being and targeting abuse and exploitation, in line with international priorities to improve conditions and health outcomes among workers globally, for example the World Health Organization’s Healthy Workplaces model for action [76].

Although this research is empirical and includes a large sample of MDWs, it is not representative of those without rest days or residing at NGO or Embassy Shelters (who often have had problems with their employers or work permits). As this study includes MDWs who may have relatively better circumstances associated with their allowance of rest days, it is anticipated that in a sample representative of all MDWs, the quality of life and social support ratings may be lower than in our findings. While the sample is limited, there were also advantages, including that it enabled qualitative data to be collected (reported elsewhere).

Additionally, the questionnaires were in English. While all participants were proficient in English, there are two important issues relating to the language of the research that should be considered. In any research in which the language of the researcher, the language of the research instruments, and the native language of the participants differ, there is the potential for the trustworthiness of the research to be affected [77]. Thus, while the participants were proficient in English and translation resources were available (though were not needed by any participants), language barriers may still have impacted on their interpretations of the questions and their responses, and consequently the data generated [78, 79]. The second issue relating to language is that the study may not be representative of MDWs who are less proficient in English, and thus who did not participate in the study, though they are likely to represent a minority of migrant domestic workers with Work Permits in Singapore given the language requirements [80]. These individuals may be more likely to be isolated, exploited, or experience barriers to accessing health or social resources, and thus experience poorer health or quality of life.

This is the first empirical study on the quality of life of migrant domestic workers in Singapore, a cosmopolitan city-state with a large non-citizen population, which has subsequently been reinforced by similar research demonstrating the mental health needs of this population in light of abuse and exploitation [59]. Overall, participants were found to have good quality of life and satisfaction with health. However more than half of participants reported feeling stressed, and nearly 20% of participants experienced isolation, both of which were associated with poorer quality of life outcomes. With globalisation and the projected increase in the need for migrant workers in many countries, there is a need for policies (e.g. access to rest days) to support their health and quality of life, and facilitate their access to coping resources [59].

However, there remains a need for further research on the health and quality of life of MDWs, including those who may be more marginalised or isolated (e.g. those unable to take advantage of a rest day). This is underscored in a recent systematic review on the health of MDWs, in which only six papers were identified that included Singaporean domestic workers in their samples, two of which used the same data [81]. Future research should look more closely into the prevalence of mental disorders among MDWs in Singapore and their correlation with abuse, in order to inform future policy. It is also worthwhile to examine whether the ASEAN Human Rights Declaration has made a difference in protecting the interests of migrant workers in Singapore, many of whom come from ASEAN countries. Applied quality of life research and comparisons of policy and practice regarding MDWs in the region and globally are necessary to provide insight into the health and quality of life of MDWs, that of their left-behind families, and their resulting needs.

Although many workers reported good social connectivity, alarmingly – especially in light of this study with MDWs who do have access to a day off – nearly one fifth reported social isolation, which was associated with poorer quality of life. The findings contribute to an evidence-base which should inform the development and implementation of policies aimed at reducing women’s exposure to stressors (e.g. exploitation, or conditions that exacerbate women’s social isolation, for example long working hours or a lack of access to days off). If effective, such measures could ultimately positively impact on female migrant domestic workers’ health and quality of life, which is a major issue in the wider ASEAN region and indeed the world.